1. Field of the Invention
The present invention relates to an automatic steering system for a vehicle for automatically parking the vehicle without recourse to steering by the driver.
2. Description of the Prior Art
Automatic steering systems for vehicles are already known from Japanese Patent Application Laid-Open Nos. 3-74256 and 4-55168. These automatic steering systems for vehicles utilize an actuator for the conventionally well-known electric power steering system, and are designed so that the back parking or the linear parking is automatically performed by controlling the actuator based on the previously stored data on the relationship between the distance of movement of the vehicle and the steering angle.
A vehicle equipped with an automatic transmission is automatically parked, while it is traveling utilizing a creep force. Therefore, it is required that a driver depresses the brake pedal during the automatic parking control to regulate the speed of the creep travel. At this time, if the amount that the brake pedal is depressed by the driver is small, there is a possibility that the vehicle creep speed will be too high, resulting in a possibility that the response of the actuator for the electric power steering system is not in time, whereby the vehicle does not move along the predetermined locus. If the amount the brake pedal is depressed by the driver is too large, there is a possibility that the vehicle creep speed is too low, whereby the time required for the automatic parking is prolonged.